The present invention relates to uninterruptible power supply systems (UPS), and more particularly, to testing UPS systems.
UPS systems are commonly used in installations such as data centers, medical centers and industrial facilities to provide backup power to maintain operation in event of failure of the primary utility supply. These UPS systems often have an “on-line” configuration including components, such as, a rectifier and inverter coupled by a DC link that is also coupled to an auxiliary power source, such as a battery, fuel cell or other energy storage device. UPS systems may include two or more UPS modules, each of which may include the components described above. The UPS modules commonly are designed to operate in parallel to provide scalable power capacity, e.g., the UPS modules may be coupled in common to an AC source, a DC source (e.g., a battery) and to a load.
UPS systems typically may be configured for testing when, for example, a diagnostic is run, which may result in the UPS systems being brought off-line. Various UPS arrangements are discussed further in, for example, U.S. Pat. No. 7,265,458 to Edelen et al., U.S. Pat. No. 7,403,364 to Anderson et al., U.S. Pat. No. 7,583,109 to Oughton Jr. et al., and U.S. Pat. No. 7,948,778 to Pfitzer et al., the disclosures of each of which are incorporated herein in their entireties.